FIG. 1 is an exploded perspective view of a related art microspeaker, and FIG. 2 is a cross-sectional perspective view of the related art microspeaker. The related art microspeaker includes a yoke 21, an inner ring magnet 22, an outer ring magnet 23, an inner ring top plate 24, and an outer ring top plate 25 installed within a frame 10, and a voice coil 30 is positioned in an air gap between the inner ring magnet 22 and the outer ring magnet 23. When power is applied to the voice coil 30, the voice coil 30 vibrates up and down. The voice coil 30 is installed on a lower surface of a suspension 40, and a side vibration plate 51 and a central vibration plate 52 are respectively installed on upper and lower surfaces of the suspension 40 and vibrate together to generate a sound according to vibration of the voice coil 30. A protector 60 is coupled to an upper side of the suspension 40 to protect components positioned within the speaker. The protector 60 includes an annular still part 61 having an opening 63 formed in a central portion thereof to emit a sound and an annular injection part 62 allowing the still part 61 to be inserted therein so as to be injection-molded and stacked on an outer circumferential portion of the side vibration plate 51 and on an outer circumferential portion of the suspension 50.
In order to apply power from the outside to the voice coil 30, the related art microspeaker includes a terminal pad 70 attached to a lower portion of the frame 10 to provide a connection point with an external terminal. The terminal pad 70 is inserted when the frame 10 is injection-molded, so that the terminal pad 70 is coupled to the frame 10 through insert injection molding.
Here, the suspension 40, to which the voice coil 30, the side vibration plate 51, and the central vibration plate 52 are attached, guiding vibration is formed of a flexible printed circuit board (FPCB) and serves to apply power from the terminal pad 70 to the voice coil 30.
Recently, mobile devices equipped with a microspeaker have reduced in thickness, and in line with this, microspeakers tend to become slimmer. However, as microspeakers are reduced in thickness, sizes of major components of the microspeakers such as a voice coil, or the like, have also been reduced in thickness, resulting in a degradation of sound characteristics. Thus, it is required to develop a microspeaker able to exhibit excellent sound characteristics, while achieving slimness.